Effects of surface porosity on tungsten trioxide(WO3) films’ electrochromic performance

Abstract

In this paper, the correlation between the electrochromic performance and the surface morphology of the tungsten trioxide (WO 3 ) thin films sputtered by dc reactive magnetron sputtering with widely varying target-substrate distances was investigated. It is found that the optical density change (∆OD) of films is strongly affected by the target-substrate distance. The coloration efficiency (CE) at 633 nm was also found to be sensitive to the target-substrate distance, with 16 cm 2 /C of film sputtered at 6 cm and 50 cm 2 /C at 18 cm. X-ray diffraction showed that the crystal structure of films was amorphous. By using atomic force microscope to identify the surface porosity of the sputtered WO 3 films, we found that the film at longer target-substrate distance was rough, porous, and having a cone-shaped columns morphology, thus offering a good electrochromic performance for opto-switching applications.

Preparation of nanostructured tungsten trioxide thin films by high pressure sublimation and condensation

“…The nanostructure seems to facilitate the diffusion of the inserted lithium atoms leading to efficient coloration. This type of correlation between surface roughness and electrochromic coloration efficiency of WO 3 films has also been observed by other authors [11].…”

The Risk Evaluation of Tungsten Oxide Nanoparticles in Cultured Rat Liver Cells for Its Safe Applications in Nanotechnology

“…It is frequently used in industry to manufacture tungstates for x-ray screen phosphors, for fireproofing fabrics and in the production of electro chromic windows and gas sensors. Due to its rich yellow color, it is also used as a pigment in ceramics and paints (Erik and Wolf-Dieter 1999;Lee 2000;Pradyot 2003;Merck Index 2006). Tungsten is also used in many military applications since it has the second highest melting temperature of any element.…”

Comparative Study of The Reactivity of the Tungsten Oxides WO₂ And WO₃ With Beryllium at Temperatures up to 1273 K

“…In consumer electronics they are used in switchable glass due to its electrochromic properties. [1][2][3] In wastewater treatment tungsten oxides are used as catalysts. [4] Modern gas sensors rely on tungsten oxides.…”